Add a helper method to set the container map and list at the same time, without
having to specify them separately. This reduces the effort required for
adding/modifying tests as well as making the code more concise.
Currently kubelet syncs all pods every 10s. This is not preferred because
* Some pods may have been sync'd recently.
* This may cause all the pods to be sync'd at once, causing undesirable
CPU spikes.
This PR replaces the global syncs with independent, periodic pod syncs. At the
end of syncing, each pod worker will enqueue itslef with a future timestamp (
current time + sync interval), when it will be due for another sync.
* If the pod worker encoutners an sync error, it may requeue with a different
timestamp to retry sooner.
* If a sync is triggered by the update channel (events or spec changes), the
pod worker would enqueue a new sync time.
This change is necessary for moving to long or no periodic sync period once pod
lifecycle event generator is completed. We will still rely on the mechanism to
requeue the pod on sync error.
This change also makes sure that if a sync does not succeed (either due to
real error or the per-container backoff mechanism), an error would be propagated
back to the pod worker, which is responsible for requeuing.
This commit builds on previous work and creates an independent
worker for every liveness probe. Liveness probes behave largely the same
as readiness probes, so much of the code is shared by introducing a
probeType paramater to distinguish the type when it matters. The
circular dependency between the runtime and the prober is broken by
exposing a shared liveness ResultsManager, owned by the
kubelet. Finally, an Updates channel is introduced to the ResultsManager
so the kubelet can react to unhealthy containers immediately.
Change all references to the container ID in pkg/kubelet/... to the
strong type defined in pkg/kubelet/container: ContainerID
The motivation for this change is to make the format of the ID
unambiguous, specifically whether or not it includes the runtime
prefix (e.g. "docker://").
Each container with a readiness has an individual go-routine which
handles periodic probing for that container. The results are cached, and
written to the status.Manager in the pod sync path.
Correct port-forward data copying logic so that the server closes its
half of the data stream when socat exits, and the client closes its half
of the data stream when it finishes writing.
Modify the client to wait for both copies (client->server,
server->client) to finish before it unblocks.
Fix race condition in the Kubelet's handling of incoming port forward
streams. Have the client generate a connectionID header to be used to
associate the error and data streams for a single connection, instead of
assuming that streams n and n+1 go together. Attempt to generate a
pseudo connectionID in the server in the event the connectionID header
isn't present (older clients); this is a best-effort approach that only
really works with 1 connection at a time, whereas multiple concurrent
connections will only work reliably with a newer client that is
generating connectionID.
Add a HostIPC field to the Pod Spec to create containers sharing
the same ipc of the host.
This feature must be explicitly enabled in apiserver using the
option host-ipc-sources.
Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
